Reducing False Detection in an Hsdpa 3G Terminal

1. A method for determining whether an encoded message in a shared channel is not intended for a communications device, the method comprising: (a) decoding the message to recover a multi-bit codeword; (b) determining whether the codeword is valid or invalid, wherein, if the codeword is determined to be invalid, then the encoded message is not intended for the communications device; and (c) if the codeword is determined to be valid, then performing one or more other steps of the method to determine whether the encoded message in the shared channel is not intended for the communications device, wherein: steps (a) and (b) are performed in parallel for a plurality of shared channels; the one or more other steps comprise: at least one single-channel step performed in parallel for each of the plurality of shared channels; and at least one multi-channel step performed for the plurality of shared channels; the at least one single-channel step comprises: (1) generating a correlation value for the codeword; and (2) comparing the correlation value to a threshold to determine whether the message is not intended for the communications device; and the at least one multi-channel step comprises: (1) selecting a shared channel having a minimum correlation value from the plurality of shared channels; (2) re-encoding and rate-matching the codeword for the selected shared channel to generate an encoded, rate-matched codeword; (3) calculating a re-encoded correlation value between the message and the encoded, rate-matched codeword; and (4) thresholding the calculated re-encoded correlation value to determine whether the message is not intended for the communications device; and the re-encoded correlation value is determined using the equation Corr = ⁢ ( ∑ i = 1 40 ⁢ S i · P i · U i ) 2 , wherein: S i is a soft bit value, P i is a re-encoded bit value, and U i is a UE scrambler bit value; and the correlation value is compared to a threshold by comparing Corr to Ene.40.Th, wherein Th is a correlation threshold, and Ene = ⁢ ∑ i = 1 40 ⁢ S i 2 .

2. The invention of claim 1 , wherein the shared channel is a High-Speed Shared Control Channel (HS-SCCH).

3. The invention of claim 1 , wherein: the message comprises a first part and a second part; the codeword is encoded in the first part; if the method does not determine that the message is not intended for the communications device, then the second part of the message is decoded.

4. The invention of claim 3 , wherein the second part of the message encodes data for demodulating another shared channel.

5. A method for determining whether an encoded message in a shared channel is not intended for a communications device, the method comprising: (a) decoding the message to recover a multi-bit codeword; (b) determining whether the codeword is valid or invalid, wherein, if the codeword is determined to be invalid, then the encoded message is not intended for the communications device; and (c) if the codeword is determined to be valid, then performing one or more other steps of the method to determine whether the encoded message in the shared channel is not intended for the communications device, wherein: steps (a) and (b) are performed in parallel for a plurality of shared channels; the one or more other steps comprise: at least one single-channel step performed in parallel for each of the plurality of shared channels; and at least one multi-channel step performed for the plurality of shared channels; the at least one single-channel step comprises: (1) generating a correlation value for the codeword; and (2) comparing the correlation value to a threshold to determine whether the message is not intended for the communications device; and the at least one multi-channel step comprises: (1) selecting a shared channel having a minimum correlation value from the plurality of shared channels; (2) re-encoding and rate-matching the codeword for the selected shared channel to generate an encoded, rate-matched codeword; (3) calculating a re-encoded correlation value between the message and the encoded, rate-matched codeword; and (4) thresholding the calculated re-encoded correlation value to determine whether the message is not intended for the communications device; and the correlation value C x is calculated by the equation C x =  V z - V l  V h - V l , wherein V z represents a zero state metric, V l represents a low state metric, and V h represents a high state metric.

6. The invention of claim 5 , wherein the shared channel is a High-Speed Shared Control Channel (HS-SCCH).

7. The invention of claim 5 , wherein: the message comprises a first part and a second part; the codeword is encoded in the first part; if the method does not determine that the message is not intended for the communications device, then the second part of the message is decoded.

8. The invention of claim 7 , wherein the second part of the message encodes data for demodulating another shared channel.

9. A communications device adapted to determine whether an encoded message in a shared channel is not intended for the communications device, the communications device comprising: one or more processors including: a decoder adapted to decode the message to recover a multi-bit codeword; a post-decoding block adapted to: (i) determine whether the codeword is valid or invalid, wherein, if the codeword is determined to be invalid, then the encoded message is not intended for the communications device, and (ii) determine whether the encoded message in the shared channel is not intended for the communications device, if the codeword is determined to be valid, wherein: the post-decoding block is adapted to determine in parallel, for a plurality of shared channels, whether the codeword is valid or invalid; the post-decoding block is adapted, if the codeword is determined to be valid, to: (i) perform at least one single-channel function in parallel for each of the plurality of shared channels, and (ii) perform at least one multi-channel function for the plurality of shared channels; the at least one single-channel function comprises: (1) generating a correlation value for the codeword; and (2) comparing the correlation value to a threshold to determine whether the message is not intended for the communications device; and the at least one multi-channel function comprises: (1) selecting a shared channel having a minimum correlation value from the plurality of shared channels; (2) re-encoding and rate-matching the codeword for the selected shared channel to generate an encoded, rate-matched codeword; (3) calculating a re-encoded correlation value between the message and the encoded, rate-matched codeword; and (4) thresholding the calculated re-encoded correlation value to determine whether the message is not intended for the communications device; the re-encoded correlation value is determined using the equation Corr = ⁢ ( ∑ i = 1 40 ⁢ S i · P i · U i ) 2 , wherein: S i is a soft bit value, P i is a re-encoded bit value, and U i is a UE scrambler bit value; and the correlation value is compared to a threshold by comparing Corr to Ene·40·Th, wherein Th is a correlation threshold, and Ene = ⁢ ∑ i = 1 40 ⁢ S i 2 .

10. The invention of claim 9 , wherein the shared channel is a High-Speed Shared Control Channel (HS-SCCH).

11. The invention of claim 9 , wherein: the message comprises a first part and a second part; the codeword is encoded in the first part; if the post-decoding block does not determine that the message is not intended for the communications device, then the second part of the message is decoded.

12. The invention of claim 11 , wherein the second part of the message encodes data for demodulating another shared channel.

13. A communications device adapted to determine whether an encoded message in a shared channel is not intended for the communications device, the communications device comprising: one or more processors including: a decoder adapted to decode the message to recover a multi-bit codeword; a post-decoding block adapted to: (i) determine whether the codeword is valid or invalid, wherein, if the codeword is determined to be invalid, then the encoded message is not intended for the communications device, and (ii) determine whether the encoded message in the shared channel is not intended for the communications device, if the codeword is determined to be valid, wherein: the post-decoding block is adapted to determine in parallel, for a plurality of shared channels, whether the codeword is valid or invalid; the post-decoding block is adapted, if the codeword is determined to be valid, to: (i) perform at least one single-channel function in parallel for each of the plurality of shared channels, and (ii) perform at least one multi-channel function for the plurality of shared channels; the at least one single-channel function comprises: (1) generating a correlation value for the codeword; and (2) comparing the correlation value to a threshold to determine whether the message is not intended for the communications device; and the at least one multi-channel function comprises: (1) selecting a shared channel having a minimum correlation value from the plurality of shared channels; (2) re-encoding and rate-matching the codeword for the selected shared channel to generate an encoded, rate-matched codeword; (3) calculating a re-encoded correlation value between the message and the encoded, rate-matched codeword; and (4) thresholding the calculated re-encoded correlation value to determine whether the message is not intended for the communications device; and the correlation value C x is calculated by the equation C x =  V z - V l  V h - V l , wherein V z represents a zero state metric, V l represents a low state metric, and V h represents a high state metric.

14. The invention of claim 13 , wherein the shared channel is a High-Speed Shared Control Channel (HS-SCCH).

15. The invention of claim 13 , wherein: the message comprises a first part and a second part; the codeword is encoded in the first part; if the post-decoding block does not determine that the message is not intended for the communications device, then the second part of the message is decoded.

16. The invention of claim 15 , wherein the second part of the message encodes data for demodulating another shared channel.